1. Field of the Invention
The invention relates to a method for automatic adjustment of sampling phase, more particularly to a method of the aforementioned type that obviates the need for a particular reference image during adjustment.
2. Description of the Related Art
During the analog-to-digital conversion stage of an image processing operation, if the sampling phase is inaccurate, the resultant image will be blurry and shaky such that a picture of clear quality cannot be obtained. Since a good phase value varies in view of different signal factors (such as rising time, falling time and ringing phenomenon), adjustment of the sampling phase is a relatively complex procedure.
There are two methods commonly employed in the adjustment of analog-to-digital sampling phase in video applications. In the first method, based on what is seen by the operator, adjustment is performed manually until shaking of the image is eliminated, and a stable image is obtained. In the second method, a particular reference image is downloaded to permit automatic adjustment. However, different reference images must be downloaded when adjusting monitors of different resolutions. Since the selection of an appropriate reference image involves some skill, use of the second method by an unskilled operator will involve a great deal of inconvenience.